A man who gets intentionally bitten by sharks insists he isn't ''fearless''.

Shark

Shark

Marine biologist Jeremiah Sullivan - who will feature in National Geographic's 'Man vs. Shark' special - has ''been bitten thousands of times'' since the early 1970s as he spends his time chronicling human-shark interactions in the name of science.

But he told the Daily Beast: ''I'm not fearless at all. Fear is a funny thing.

''Fear of the unknown is really all it comes down to, so if you're well-informed about the environments you're going into, and prepared as can be, it puts you in a pretty good position. ''Being a water guy and in the ocean virtually my whole life, it's not something that's frightening or fearful to me. It's more like home.''